Traditional laser projection systems face significant challenges when projecting onto large objects, mainly due to their limited projection range. Projection errors are positively correlated with parameters such as projection angle and projection distance, and it is not advisable to increase the projection distance to extend the projection range. Furthermore, if the projection environment is relatively narrow, it is impossible to extend the projection range by increasing the projection distance. Frequent station changes and repeated calibration are required. This limitation leads to the need for multiple recalibrations to position the projected object, which requires the arrangement of complex cooperative target points and increases the calibration time, which greatly reduces the overall efficiency. To solve these problems, this study introduces an innovative omnidirectional industrial laser projection positioning system that integrates a dual-axis turntable, which can project 360° without the need for repeated calibration, thereby improving projection efficiency and expanding the effective projection range. For the omnidirectional industrial laser projection positioning system integrating a dual-axis turntable constructed in this paper, a calibration method based on the four-axis rotation angles of both the dual-axis galvanometer and the dual-axis turntable is proposed. First, a calibration model is established for the system construction parameters, which are the relative poses between the 3D laser projection system and the dual-axis turntable. In principle, calibration only needs to be performed before the unit leaves the factory or when accessories are replaced, and does not need to be repeated in the field. Specifically: 1) use a laser tracking system to separately position the dual-axis turntable and the multi-parameter integrated calibration plate to obtain the relative pose of the laser tracker with respect to each of the two; 2) use the laser 3D projection system to position and calibrate the multi-parameter integrated calibration plate to obtain the relative pose between the two; 3) the relative pose between the dual-axis turntable and the laser 3D projection system, i.e. the system construction parameters, can be obtained from the above relative pose relationship. Next, three sets of cooperative target points were set up in three different directions, with two cooperative target points in each set. The rotation angles of the dual-axis galvanometer of the laser 3D projection system and the pitch and roll angles of the dual-axis turntable were recorded when calibrating each set of cooperative target points. Based on the four-axis rotation angles of the dual-axis galvanometer and dual-axis turntable corresponding to different cooperative target points, a system external parameter calibration model is established. Based on the dual-axis turntable coordinate system, the relative pose between the laser 3D projection system coordinate system and the projected object coordinate system is obtained and the pose change is monitored in real time. Finally, an objective optimisation function is constructed for the calibration model, and a sequential least squares optimisation algorithm is used to solve for the calibration parameters. According to the working characteristics of the omnidirectional industrial laser projection system, such as the projection range and the distance of the projector, the starting point is chosen close to the feasible solution domain. A multi-start strategy and the current value of the objective function are used to find the global optimal solution, ensuring accurate determination of the calibration parameters. For the above strategy, the RMS value of the error calculated by the six cooperative target points is used as a reference. The results of 100 repeated calculations using the above algorithm show that the above strategy is sufficient to allow the algorithm to find a solution with global optimal properties for the problem given in this paper, and the calculation meets the accuracy requirements of the simulation. The accuracy of the calibration model was verified by simulation, and the simulation results showed that the theoretical accuracy reached 10^-6 mm. Under the simulation of normal distribution errors, the average calibration accuracy of the system was maintained at 0.242 mm. The experiment of system construction parameter calibration verified the stability and accuracy of the verification system construction parameter calibration. By causing the dual-axis turntable to rotate a fixed angle, the relative pose between the laser 3D projection system and the dual-axis turntable after the rotation of the dual-axis turntable was calibrated and the dual-axis turntable, comparing it with the relative pose between the laser 3D projection system and the dual-axis turntable after the rotation of the dual-axis turntable obtained by solving the system construction parameter calibration model, and calculating the absolute deviation (translation matrix and rotation matrix) between the two. The experimental results show that the absolute deviation of the rotation matrix of the two positions can reach the level, and the absolute deviation of the translation matrix can reach 0.023 mm. To verify the omnidirectional projection accuracy, a system external parameter calibration experiment was designed. Three multi-parameter integrated calibration plates were used to simulate the scene of projection and positioning of a large projected object. The experimental results further proved that the system can dynamically adjust the posture of the 3D laser projection system relative to the projected object through the dual-axis turntable, thereby achieving omnidirectional projection (360°). The maximum position deviation is about 0.30 mm, which meets industrial accuracy standards.